CN1694851A - Surfactant-mediated porous metal oxide membranes - Google Patents

Abstract

The present invention provides surfactant mediated metal oxide films that are hydrophilic and articles having hydrophilic films of the invention on one or more surfaces.

Description

Surfactant-mediated porous metal oxide membranes

background

The invention relates to a hydrophilic porous carrier metal oxide film.

A hydrophilic surface is beneficial for its anti-fog properties. "Anti-fogging" broadly refers to preventing or minimizing the occurrence of optical distortion caused by fogging, formation of condensation droplets, or water droplets adhering to surfaces.

Many surface treatments have been proposed with varying degrees of success. For example, the application of hydrophilic or hydrophobic compounds has been used to provide anti-fog surfaces. However, the anti-fog effect is temporary because compounds such as polyethylene glycols and silicones are relatively easy to remove when exposed to water. Various types of surfactants have also been proposed. However, these surfactants have also been shown to be transient.

US Patent No. 6013372 reports anti-fog coatings comprising titanium dioxide. The coatings are generally produced by depositing a composition comprising a source of titanium dioxide, an acid and a solvent onto a substrate, drying the composition, and then calcining. The coating composition also contains silica or tin particles.

US Patent No. 5858457 reports a method of making very regular porous support metal oxide membranes with surfactants. The coating has a Bragg peak in the X-ray diffraction (XRD) pattern using Cu K _alpha radiation at 2-6° 2Θ.

PCT Publication No. WO99/37705 reports metal oxide materials with surfactants which are very regular and have large pore sizes.

overview

One aspect of the invention provides a metal oxide film with a surfactant interposed therebetween. The metal oxide film mediated by the surfactant of the present invention is porous, its pore size is nanometer, and under the condition of using Cu K _α radiation, there is no XRD peak when it is less than 5° 2θ (that is, only at 5° peaks at 2θ and above). The surfactant-mediated metal oxide film of the present invention has highly disordered pores.

"Surfactant-mediated membrane" refers to a nanoporous membrane whose pores do not exhibit long-range order, and more than 20% (preferably more than 50%) of the pores are continuous (substantially without interruptions, such as cracks), More than 50% (preferably more than 90%) of the nanopores have a pore diameter of 0.1-50 nm (preferably 1-10 nm); the membrane with the surfactant of the present invention is preferably transparent. The surfactant-mediated films do not have low-angle Bragg peaks when analyzed using XRD with Cu K _α radiation. The pores of the surfactant-mediated membranes of the present invention can penetrate the surface of the membrane when the surface is nanometer roughened.

In contrast, the "surfactant-templated film" provides small-angle peaks and exhibits long-range ordered pores when analyzed using Cu _Kα radiation. In many cases, most of the pores of a membrane with surfactant are impermeable to the surface of the membrane.

The membrane mediated by the surfactant of the present invention can provide a superhydrophilic surface, and it is confirmed that the contact angle with water is less than 10°, preferably less than 5°. The contact angles of the films of the present invention are small and long-lasting. Films made by the sol-gel process and certain films of the present invention (eg, titanium dioxide) regenerate faster on exposure to UV light. "Regeneration" is indicated by a change in contact angle from greater than 10° to less than 10°. In addition, due to the high porosity and lower refractive index of surfactant-mediated films, the intensity of interference colors is lower for surfactant-mediated films than for denser films. This provides a film with lower surface coloration in viewing angle.

Brief description of the drawings

FIG. 1 is an X-ray diffraction diagram of Comparative Example 1 and Sample 6 shown in Table 5.

Figure 2 shows digital images of high resolution field emission scanning electron micrographs of representative samples 1A-I of the surfactant-mediated titania shown in Table 9.

Figure 3 shows digital images of high resolution field emission scanning electron micrographs of representative Comparative Examples CE2A-CE2I of sol-gel formed titania.

detail

The surfactant-mediated metal oxide (SMM) films of the present invention are typically formed by applying a SMM precursor composition to a substrate, evaporating the solvent to form a thin metal oxide-surfactant film and removing all prepared using the above surfactants.

The SMM precursor composition is prepared by selecting reagents and conditions such that the surfactant does not strictly template (sequence) the inorganic phase definition, but provides random nanoporosity to the inorganic phase , such that the volume percent porosity is greater than about 20%, preferably greater than about 50%. Reagents and conditions are generally chosen such that the spontaneous surfactant ordering that occurs as the coated precursor composition dries does not dominate the overall structural orientation. This can be achieved by selecting alkoxides that hydrolyze and condense rapidly (e.g., titanium ethoxide in the presence of hydrochloric acid and water), allowing random, irregular sol-gel reactions and spontaneous ordering of surfactants to compete into liquid crystalline structures; or By choice of conditions (e.g., temperatures close to the Krafft point, or high temperatures where long-range order is disrupted by thermal effects, or use of co-solvents/additives that disrupt the order of micelles, such as medium-chain-length alcohols with alkylammonium surfactants) , making the surfactant an edge liquid crystal forming agent to complete.

The SMM precursor composition includes a soluble source of metal oxides. Examples of soluble metal oxide sources include titanium alkoxides such as titanium butoxide, titanium isopropoxide, titanium ethoxide, titanium peroxide and titanium diisopropoxide bis(2,4-pentanedipyruvate) , and alkoxysilanes such as tetramethoxysilane and tetraethoxysilane and combinations thereof. Other sources include alkoxides and molecular salts of metals such as zirconium, hafnium, vanadium, molybdenum, tungsten, magnesium, iron, cobalt, nickel, copper, zinc, aluminum, gallium, indium, germanium, tin, arsenic, and antimony.

The SMM precursor composition comprises one or more surface activity mediators (surfactants). The surface active mediator can be cationic, nonionic or anionic, and can also be fluorinated. Useful cationic surfactants include those having the general formula C _n H _2n+1 N(CH ₃ ) ₃ X (wherein, X is OH, Cl, Br, HSO ₄ or a combination of OH and Cl, n is an integer of 8-22 ) and alkyl ammonium salts of the general formula C _n H _2n+1 N(C ₂ H ₅ ) ₃ X (where n is an integer of 12-18); gemini surfactants, such as having the general formula (C ₁₆ H ₃₃ N(CH ₃ ) ₂ ) 2C _m H _2m 2X (wherein, m is an integer of 2-12, and X is as described above); and hexadecylethylpyridinium salts, for example, C ₁₆ H ₃₃ N( C ₂ H ₅ )(C ₅ H ₁₀ )X (wherein, X is as described above).

Useful anionic surfactants include alkyl sulfates, for example _, having the general formula _{CnH2n + 1OSO4Na} (where n is 12-18); _{alkylsulfonates} , such as _C12H25C6 H ₄ SO ₄ Na; and alkyl carboxylic acids such as C ₁₇ H ₃₅ COOH and C ₁₄ H ₂₅ COOH.

Other useful anionic surfactants include, but are not limited to, the alkali metal and (alkyl)ammonium salts of: 1) the sulfate salts of polyethoxylated derivatives of linear or branched aliphatic alcohols and carboxylic acids; 2) alkylbenzene or alkylnaphthalene sulfonates and sulfates, such as sodium octylbenzenesulfonate; 3) alkyl carboxylates, such as dodecyl carboxylate; and 4) ethoxylated and poly Ethoxylated alkyl and aralkyl alcohol carboxylates.

Useful nonionic surfactants include poly(ethylene oxide), (octaethylene glycol) monolauryl ether (C ₁₂ EO ₈ ), (octaethylene glycol) monohexadecyl Ethers (C ₁₆ EO ₈ ) and poly(alkylene oxide) triblock copolymers such as poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) Or reverse (PPO-PEO-PPO). Examples of useful commercially available nonionic copolymer surfactants include those available under the tradename PLURONIC and product designations P123, F98, 25R4, and 17R4 from BASF Corporation, Mount Olive, NJ.

Another useful organic templating reagent is the ethoxylated amines, also known as ethoxylated fatty amines. Preferred _ethoxylated amines have the general formula RN( _CH2CH2O )XH( _CH2CH2O )yH (where x+y=15-50), commercially available _from Akzo Nobel, Chicago, IL Bought from ETHOMEEN.

Organic solvents may be used in the SMM precursor composition. Useful organic solvents include alcohols such as ethanol, methanol, isopropanol and other medium dielectric constant solvents such as ketones, furans, amides, polyols, nitriles including acetone, tetrahydrofuran, N-methylformamide, formamide, glycerol , acetonitrile, ethylene glycol and their mixtures. Water used in SMM compositions is typically deionized.

The SMM composition may contain one or more acid catalysts. Useful acid catalysts include organic and inorganic acids. Specific examples include acetic acid, nitric acid and hydrochloric acid.

In some embodiments, the SMM precursor composition and resulting film comprise nanoparticles. Useful nanoparticles include, for example, metal oxides of silicon, titanium, aluminum, antimony, arsenic, zirconium, tin, and rare earth and transition metal oxides. Specific examples include colloidal silica and titania nanoparticles. Specific examples include Nalco 1042 (20nm) colloidal silica from Nalco Chemical Co., Naperville, IL; 8, 9 and 12nm Optolake titanium dioxide particles from Catalyst and Chemicals Ind.Co.Ltd., Kawasaki City, Japan; and 30nm Titanium dioxide/antimony particles (prepared by mixing a soluble source of titanium dioxide with a soluble source of antimony, and heating and pressurizing the mixed source in an autoclave at 150-200° C. for 5 hours, as published on June 5, 2003 described in PCT publication WO 03/045846).

Usually, the molar ratio of the components in the composition is 20-140 moles of solvent, 0.1-26 moles of water, and 0.001-1.0 moles of surface active mediator per mole of metal oxide. In other embodiments, the molar range is 40-60 moles of solvent, 0.1-5 moles of water, and 0.05-0.4 moles of catalyst per mole of metal oxide. The volume ratio of the metal oxide and the surfactant is usually 10-0.1. Nanoparticles can be used in the SMM precursor composition in an amount up to about 30% by volume.

The thickness of the SMM film of the present invention is generally from 10 nm to about 1 micron, and can be any thickness or thickness range therein, and/or have about greater than 20% to about 90%, preferably greater than 50% to 90% of the pores , and/or a refractive index of 1.2-2.15 (any range between 1.2 and 2.15 or a single refractive index) without nanoparticles; a refractive index of 1.35 up to 2.1 (between 1.35 and 2.1) with nanoparticles any range in between or a single index of refraction). Films with a porosity greater than about 50% typically have a refractive index of less than 1.7.

The SMM film of the present invention is prepared by coating the SMM precursor composition of the present invention onto a surface. The SMM precursor composition can be applied to the surface by any known method such as dip coating, spin coating, spray coating or gravure coating. The coated surface is dried at room temperature, or optionally heated at slightly elevated temperature. Once the coating is substantially dry, the coating can be treated to remove substantially all of the surface active mediator.

Typically, the metal oxide-surfactant film is calcined at a sufficient temperature for a sufficient time to remove the surfactant mediator and form an SMM film. Typical calcination temperatures range from about 200-850°C, including any temperature and temperature range between 200-850°C. Typical calcination times range from about 0.01 to about 10 hours, including any time and time range between 0.01 to 10 hours, such as about 0.5 to 2 hours. The actual calcination time will vary depending on the type and amount of surfactant used.

The SMM films of the present invention can be used on a variety of substrates where hydrophilicity and/or antireflection are useful properties of the substrate surface. These include substrates made of metals, colored metals, glass, ceramics, wood, and the like. Examples of such substrates include mirrors, lenses, eyeglasses, optical components, instrument covers, signs, windows, tiles, retroreflective articles, metals, windshields, face shields, and various medical implements and supplies. The SMM films described herein can also be used as one or more layers in an antireflection stack.

The surface of the substrate may also have an inert barrier film between the surface of the substrate and the SMM film. Examples of such inert films include films comprising silicon dioxide or silicone. For example, this inert film provides a barrier layer between the surfactant-mediated titania film and the glass substrate, preventing the transfer of alkali metals from the glass into the titania.

Example

Glossary of terms

10R5 is a PPO-PEO-PPO triblock copolymer surfactant commercially available from BASF under the trade designation "PLURONIC 10R5".

P123 is a PEO-PPO-PEO triblock copolymer surfactant commercially available from BASF under the trade designation "PLURONICP123".

P103 is a PEO-PPO-PEO triblock copolymer surfactant commercially available from BASF under the trade designation "PLURONICP103".

" _C16 TAB" is cetyltrimethylammonium bromide, commercially available from Aldrich Chemical Company, Milwaukee, WI.

" _C₁₆TAB " is tetradecyltrimethylammonium bromide, commercially available from Aldrich Chemical Company.

general method

Substrate Cleaning Procedure

Glass substrates (VWRMicroSlides, pre-cleaned 25 × 75 mm, VWR Scientific Inc, West Chester, PA) and ≤100 ≥ cut, p-type, B-doped silicon were cleaned by sonication for 2 min in LIQUINOX/DI water solution Sheets (3″ from Silicon Sense, Nashua, NH). The substrates were then rinsed with deionized water for 2 minutes and rinsed with ethanol prior to coating.

2.16M TEOS sol

Tetraethoxysilane (TEOS) (223 mL, available from Aldrich Chemical Company), absolute ethanol (223 mL, available from Aaper Alcohol, Shelbyville, KY), deionized water (17.28 mL), and 0.07N hydrochloric acid (0.71 mL) Mix in a 2L reaction flask. The resulting clear solution was heated to 60°C and stirred for 90 minutes. The solution was allowed to cool and transferred to a plastic bottle and stored in a 0°C refrigerator. The solution is expected to be stable for more than 5 years. The resulting solution had a concentration of 2.16M SiO2.

Thickness (t) and Refractive Index (n)

Data (psi and δ) of SMM films on silicon wafers were measured at 50° and 70° using a Gaertner L116A ellipsometer (Skokie, IL) with a HeNe 632 nm laser. At least 3 points were measured for each sample. Reported values are averages. By assuming a single layer film, thickness and refractive index were determined from psi and delta using software provided by the supplier. The parameters of the substrate are index Ns=3.850, absorption coefficient Ks=-0.020.

Contact Angle (CA)

Static water contact angles were collected using a VCA 2500 XE (available from AST Products, Billerica, MA). Typically, a 1 microliter droplet of deionized water was transferred to the substrate and a digital map of the diffused droplet was reported after 10 s. The contact angle is determined automatically using in-house software. For contact angles less than 15°, the contact angle must sometimes be determined manually because the software program does not correctly identify the edges of the water droplet. Use at least two water droplets per substrate. Take the average of the data. For dip-coated films on glass, the contact angles at the top and bottom of the substrate are reported.

X-ray diffraction (XRD)

Small angle diffraction data were collected using a high resolution diffractometer, copper K _alpha radiation, and scintillation detection of scattered radiation. To examine the crystallinity (20-60° 2Θ) of titania, data was collected using a Philips APD vertical diffractometer, copper K _alpha radiation, reflection geometry, and a ratio detector.

Photocatalytic activity test (PA)

A 4×10 ^-4 M aqueous solution of sodium terephthalate was prepared. This solution (100 mL) was added to a 500 mL crystallization dish along a magnetic stir bar. One 25 x 75 mm SMT-coated glass substrate was added to each dish. Under stirring conditions ^, the samples were immediately placed under ~2.0 mW/C _m2 UV source (UVB black light model XX-15L (Upland, CA). Aliquots (1 mL) were removed every 5 minutes and analyzed with a spectrophotometer (Spex FluoroMax-3, JY Horiba, Spex Fluorescence Division, Edison, NJ) analysis is from the fluorescence of 2-hydroxyterephthalic acid. The spectrophotometer has the excitation source of 315nm, monitors the fluorescence at 424nm place. Draw intensity and A plot of the data over time and a linear function is fitted to said data. These data are called "onset slopes," with higher slopes indicating more active substances.

pencil hardness

Data were determined according to ASTM D3363-92a and ECCA T4 (1984) using a Wolff-Wilborn pencil test apparatus from Gardco (Pompano Beach, FL). Experiments were carried out using 17 pencil leads from 6B to 9H.

Aging data

According to ASTM G-155, Cycle 1 test SMM film on glass, here, the UV source is a xenon arc lamp, the cycle time is 102 minutes at 62°C with a daylight filter (0.35W/m2/nm at 340nm) , and then exposed to sunlight for 18 minutes under water spray, the entire test time is 500 hours.

Surfactant volume % (V% Surf)

The approximate volume ratio of surfactant (S) to inorganic (I) in the SMM precursor composition is determined as follows:

V%Surf＝100×(V _S /(V _S +V _I )) (1)

In the formula, _V is determined by the molecular weight and density of the surfactant (assumed to be 1 g/cc), and _V is determined by the molar number, molecular weight and density of the metal oxide (for example, for titanium dioxide that is anatase, FW =79.88g/mol, density=3.84g/cc). The formula is _VI = number of moles x FW/density.

Porosity (%P)

The partial porosity is calculated from the refractive index data according to the Lorentz-Lorenz equation:

P=1-[((n _anatase ² -1)/(n _anatase ² +2 ₎ )/((n calcined ² -1)/(n _calcined ² +2))] (2)

where n _anatase is 2.53 and n _calcined is the refractive index of the calcined film determined by ellipsometry. Where there is a mixed metal oxide structure, the molar average refractive index is used. N=1.458 was used as an index for silica.

Porosity % is %P=100*P (3)

Example 1

Mix titanium ethoxide (Aldrich Chemical Company), absolute ethanol, P123, and concentrated hydrochloric acid in a 250 mL polypropylene bottle in the amounts shown in Table 1. The mixture was stirred at room temperature at 300 rpm prior to coating. The mixtures all formed clear colorless solutions.

Table 1 Example 1 (sample) Ti(OC ₂ H ₅ )4(mL) Ethanol (mL) P123(g) HCl(mL) 1 7.59 77.2 0.25 0.57 2 7.59 77.2 0.5 0.57 3 7.59 77.2 1 0.57 4 7.59 77.2 2 0.57 5 7.59 77.2 3 0.57 6 7.59 77.2 4 0.57 7 7.59 77.2 5 0.57

The molar ratios of the reagents are shown in Table 2.

Table 2 sample Ti(mol) Ethanol (mol) P123(mol) HCl (mol) water (mol) 1 1 35.7 0.0012 0.188 0.650 2 1 35.7 0.0024 0.188 0.650 3 1 35.7 0.0047 0.188 0.650 4 1 35.7 0.0094 0.188 0.650 5 1 35.7 0.0142 0.188 0.650 6 1 35.7 0.0189 0.188 0.650 7 1 35.7 0.0236 0.188 0.650

Before coating, the above solution was filtered through a 0.2 micron PTFE filter to remove dust. Coating was performed in a still air atmosphere at ambient humidity, and the glass and silicon substrates were cleaned as described above. The substrate is suspended from a clamp attached to a variable speed coating arm and dipped. The immersion and withdrawal speed is 0.5C _m /s. The film dries within 1 minute. The films were dried at room temperature for 3 days and calcined at 500°C for 1 hour.

For films on silicon substrates, thickness (t25°C) and refractive index (n25°C) were measured at 50° and 70° as described above. Contact angle (CA), refractive index (n500°C) and thickness (t500°C) were measured after calcination. The approximate volume percent of surfactant in the coating mixture was calculated as described above (in Equation 1). X-ray diffraction with Cu _Kα was examined from 0.5–60° 2θ as described above. No Bragg peak was observed for any sample.

Thickness, index of refraction, % porosity, and volume % surfactant in coating solutions for films on silicon substrates are shown in Table 3.

table 3 sample t25℃() n25℃ t500℃() n500℃ %P at 500°C V%Surf 1 3696 1.73 876 1.74 37 25 2 4117 1.69 1034 1.84 31 39 3 3828 1.87 914 1.85 31 57 4 3152 1.64 1271 1.62 45 72 5 3983 1.66 1627 1.49 55 80 6 3091 1.57 2023 1.39 63 84 7 4058 1.57 2287 1.35 67 87

For film samples on glass, the contact angle of the samples on glass was monitored, after which time-photocatalytic test data were collected as described above. The samples were placed horizontally on the bench and the data are for the side of the film facing up. The samples were UV treated with a black light (~2mW/ _Cm2 ) for 30 minutes. Pencil hardness data were also measured on all calcined samples using the method described above. The contact angle, photocatalytic activity, pencil hardness and X-ray diffraction data of the film on glass are shown in Table 4.

Table 4 sample CA(°) CA(°) CA(°) CA(°) CA(°) CA(°) Photocatalytic data pencil hardness XRD XRD sky 1 3 8 15 15 45 45 as made Calcination at 500°C (2 days in total) Uncovered (total 7 days) Uncovered (14 days total) UV.30 minutes (total 14 days) After photocatalytic test (total 44 days) Starting slope (intensity/minute) (total 44 days) 2θ<5° 20°＜2θ＜60° 1 20 2 10 twenty four 9 10 7001 2H - - 2 9 3 6 10 8 18 5943 2H - - 3 8 4 6 15 10 12 5072 5B - - 4 14 4 5 5 4 16 10155 5B - - 5 17 4 8 6 5 10 12046 <6B - - 6 18 2 4 5 4 10 12700 <6B - - 7 twenty four 5 5 10 4 11 24400 <6B - -

Note: - indicates that there is no Bragg peak in this range.

Example 2

Mix titanium ethoxide, absolute ethanol, C ₁₄ TAB and concentrated hydrochloric acid in a 250 mL polypropylene bottle, and the amounts are shown in Table 5. The mixture was stirred at room temperature at 300 rpm before coating. The mixtures all formed clear colorless solutions. Comparative Example 1 is a control sample without surfactant. FIG. 1 shows the X-ray diffraction patterns of Sample 6 and Comparative Example 1.

table 5 sample Ti(OC ₂ H ₅ )4(mL) Ethanol (ml) C14TAB(g) HCl (ml) Comparative example (CE) 1 7.59 77.2 0.0 0.57 1 7.59 77.2 0.5 0.57 2 7.59 77.2 1 0.57 3 7.59 77.2 2 0.57 4 7.59 77.2 3 0.57 5 7.59 77.2 4 0.57 6 7.59 77.2 5 0.57

The molar ratios of the reagents are shown in Table 6.

Table 6 sample Ti(mol) Ethanol (mol) C ₁₄ TAB (mol) HCl (mol) water (mol) CE1 1 35.7 0.00 0.188 0.650 1 1 35.7 0.040 0.188 0.650 2 1 35.7 0.081 0.188 0.650 3 1 35.7 0.161 0.188 0.650 4 1 35.7 0.242 0.188 0.650 5 1 35.7 0.323 0.188 0.650 6 1 35.7 0.404 0.188 0.650

The above coating solution was filtered and coated as described in Example 1. The film dries within 1 minute. Films 4-6 appeared slightly hazy immediately after drying. The film was dried at room temperature for 3 days.

For films on silicon substrates, thickness and refractive index were measured at 50° and 70° as described above. Then, the film was calcined at 500°C for 1 hour. Contact angle, refractive index, and thickness were again measured. The approximate volume % of surfactant in the coating mixture is calculated as above. Thickness, refractive index (70° data), % porosity, and volume % surfactant in coating solution for films on silicon substrates are shown in Table 7.

Table 7 sample t25℃() n25℃ t500℃() n500℃ %P at 500°C V%Surf CE1 1648 1.77 1318 2.06 40 0.0 1 1642 1.73 1507 1.84 31 0.39 2 1895 1.75 1562 1.86 30 0.57 3 2704 1.64 1650 1.81 33 0.72 4 3240 1.61 1654 1.80 34 0.80 5 3771 1.70 1738 1.74 37 0.84 6 4026 1.54 1790 1.80 34 0.87

For samples on glass, the contact angle was monitored over 48 days. The membranes were placed horizontally in petri dishes on a benchtop. Unless otherwise stated, the contact angle data are for the upward (top) side of the sample. Photocatalytic data were collected after calcination as described above. Pencil hardness data was also measured on all calcined samples using the method described above. X-ray diffraction with Cu _Kα was examined from 0.5–60° 2θ as described above. No Bragg peak was observed for any sample. The contact angle, photocatalytic activity, pencil hardness and X-ray diffraction data of the film on glass are shown in Table 8.

Table 8 sample CA(°) CA(°) CA(°) CA(°) CA(°) Photocatalytic data pencil hardness XRD XRD Total days since made 1 4 11 48 48 14 Made Calcined at 500°C not covered not covered bottom Initial slope (intensity/minute) 2θ<5° 20°＜2θ＜60° CE1 40 3 3 twenty four 7 46000 5H - A 1 8 3 3 15 6 54000 5B - A 2 8 2 3 14 6 60000 3B - A 3 8 2 3 12 5 46000 2B - - 4 9 2 4 20 6 60000 2B - - 5 12 2 5 11 8 59000 3B - - 6 14 2 2 6 4 43000 6B - A

Note: - indicates no Bragg peak in this range; A indicates anatase; in all cases the peaks are weak, indicating that only a small fraction of titanium dioxide was converted under these conditions.

Example 3

Titanium ethoxide (Aldrich Chemical Company), absolute ethanol, P123 and concentrated hydrochloric acid were mixed in a 250 mL polypropylene bottle in the amounts shown in Table 9. The mixture was stirred at room temperature at 300 rpm prior to coating. The mixtures all formed clear colorless solutions. CE2A-I is a sol-gel sample without surfactant. Figures 2 and 3 show representative digital images of high-resolution field emission scanning electron micrographs of surfactant-mediated titania and sol-gel-forming titania, respectively.

Table 9 sample Ti(OC ₂ H ₅ )4(mL) Ethanol (mL) P123(g) HCl(mL) 1A-I 7.59 77.2 4.62 0.57 CE 2A-I 7.59 77.2 0.0 0.57

The molar ratios of the reagents are shown in Table 10.

Table 10 sample Ti(mol) Ethanol (mol) P123(mol) HCl (mol) water (mol) 1A-I 1 35.7 0.022 0.188 0.650 CE 2A-I 1 35.7 0.00 0.188 0.650

10 samples each were coated with solutions 1 and 2. The above coating solution was filtered and coated onto a substrate as described in Example 1. The film dries within 1 minute. The film was dried at room temperature for 1 day.

For films on silicon, thickness and refractive index were measured at 50° and 70° as described above. The films were then treated at the temperatures shown in Table 11 below. Contact angle (CA), refractive index (n) and thickness (t) were again measured. The approximate volume percent of surfactant in the coating mixture was calculated to be 86%, as described above. The thickness and refractive index of the films on silicon are shown in Table 11.

Table 11 sample temperature(℃) t() t() no no 1 CE2 1 CE2 A room temperature 2930 1299 1.54 1.74 B 100 2991 1054 1.56 1.92 C 200 3178 982 1.57 1.99 D. 250 2451 941 1.37 2.02 E. 300 No 894 No 2.00 f 400 1744 771 1.56 1.93 G 500 1566 750 1.52 1.94 h 650 1437 647 1.58 2.11 I 800 1361 563 1.77 2.21

For film samples on glass, the contact angle was monitored over 25 days. The samples were placed horizontally in a Petri dish on a laboratory bench. Unless otherwise stated, the contact angle data are for the upward (top) side of the sample. The contact angles of the films on glass are shown in Table 12. NT means "not tested".

Table 12 sample CA(°)1 CA(°)CE2 CA(°)1 CA(°)CE2 CA(°)1 CA(°)CE2 CA(°)1 CA(°)CE2 CA(°)1 CA(°)CE2 Total days since made 1 1 2 2 6 6 15 15 25 25 as made as made calcined calcined Uncovered (4 days after calcination) Uncovered (4 days after calcination) Coverage (9 days total) Coverage (9 days total) After photocatalytic test After photocatalytic test A 20 25 19 35 11 62 13 72 - - B twenty two 25 16 54 19 67 15 83 - - C twenty two twenty four 10 40 10 58 twenty four 51 - - D. twenty two twenty three 16 32 31 63 28 52 - - E. twenty two twenty three 11 14 twenty one 48 18 44 13 39 f twenty three 25 3 3 5 10 16 20 9 14 G 19 twenty four 1 3 5 7 15 18 7 25 h twenty two 25 0 1 3 5 13 16 12 26 I twenty one 29 NT NT NT NT NT NT NT NT

Photocatalytic data were collected after calcination as described above. The samples were UV treated with a UVB black lamp (~2mW/ _Cm2 ) for 30 minutes. Pencil hardness data were also measured on all calcined samples using the method described above. X-ray diffraction with Cu _Kα was examined from 0.5–60° 2θ as described above. No Bragg peak was observed for any sample.

Table 13 Initial slope (counts/minute) Initial slope (counts/minute) pencil hardness pencil hardness sample 1 CE2 1 CE2 A <6B <6B B <6B 3B C <6B B D. <6B Hb E. 1700 3000 <6B f f 2200 2000 <6B 3B G 23000 1000 <6B 3B h 82000 26000 <6B 2H I no data no data <6B >9H

Example 4

Mix titanium ethoxide, absolute ethanol, concentrated hydrochloric acid, 2.16M TEOS sol and P123 in sequence in a 250mL polypropylene bottle, and the amounts are shown in Table 14. The mixture was stirred at room temperature at 300 rpm prior to coating. The mixtures all formed clear colorless solutions.

Table 14 sample Ti(OC ₂ H ₅ )4(mL) 2.16M TEOS Ethanol (mL) P123(g) HCl(mL) 1 7.59 0.00 77.2 4.62 0.57 2 6.64 2.13 77.2 4.62 0.57 3 5.69 4.27 77.2 4.62 0.57 4 3.8 8.53 77.2 4.62 0.57 5 1.9 12.80 77.2 4.62 0.57 6 0.00 17.06 77.2 4.62 0.57

Note: Samples 7-12 are similar to samples 1-6 except they contain 1.00 g P123.

The molar ratios of the reagents are shown in Table 15.

Table 15 sample Ti(mol) Si(mol) Ethanol (mol) P123(mol) HCl (mol) water (mol) 1 1 0 35.7 0.022 0.188 0.650 2 0.825 0.125 35.7 0.022 0.188 0.650 3 0.75 0.25 35.7 0.022 0.188 0.650 4 0.50 0.50 35.7 0.022 0.188 0.650 5 0.25 0.75 35.7 0.022 0.188 0.650 6 0 1 35.7 0.022 0.188 0.650

Note: For samples 7-12, the molar ratios are the same except that the ratio of P123 is 0.0047.

The above coating solution was filtered and coated onto a substrate as described in Example 1. The film was dried at room temperature for 1 day.

For films on silicon substrates, thickness and refractive index were measured at 50° and 70° as described above. Then, the film was calcined at 500°C for 1 hour. Contact angle, refractive index, and thickness were again measured. The approximate volume % of surfactant in the coating mixture is calculated as above. Thickness, refractive index (70° data), % porosity, and volume % surfactant in coating solution for films on silicon are shown in Table 16.

Table 16 sample t25℃() n25℃ t500℃() n500℃ %P at 500°C V%Surf 1 4683 1.49 2090 1.39 63 86 2 3680 1.49 1100 1.79 31 85 3 3226 1.53 1489 1.69 34 85 4 3011 1.58 1315 1.64 28 84 5 2982 1.63 1599 1.54 twenty one 83 6 3555 1.35 1747 1.35 twenty one 81 7 3852 1.52 1099 1.79 34 57

8 2647 1.50 937 1.72 36 56 9 2772 1.56 1197 1.79 27 55 10 2631 1.45 1142 1.67 25 53 11 2157 1.48 1238 1.49 27 51 12 2077 1.42 1259 1.33 25 50

For samples on glass, the contact angle was monitored over 7 days. The samples were placed horizontally in a Petri dish on a laboratory bench. Unless otherwise stated, the contact angle data are for the upward (top) side of the sample. Photocatalytic data were collected after calcination as described above. The samples were UV treated with a UVB black lamp (~2.0 mW/C _m ² ) for 30 minutes. Pencil hardness data was also measured on all calcined samples using the method described above. The data for the films on glass are shown in Table 17.

Table 17 sample CA(°) CA(°) CA(°) CA(°) Photocatalytic data pencil hardness days since made 0 1 6 7 14 as made Calcined at 500℃ After TPA test not covered Initial slope (intensity/minute) 1 17 3 9 9 25659 <6B 2 27 2 14 9 1193 2B 3 28 2 9 5 860 2B 4 46 1 34 26 256 2B 5 53 1 15 38 346 1B 6 84 1 19 10 259 7H 7 8 2 14 6 9900 <6B 8 27 3 12 6 1220 1B 9 28 3 9 4 988 2B 10 45 2 twenty two 17 173 1B 11 47 2 4 13 875 HB 12 55 1 3 4 922 HB

Example 5

Titanium ethoxide, absolute ethanol, concentrated hydrochloric acid, 2.16M TEOS sol and P123 were mixed in sequence in a 250mL polypropylene bottle, and the amounts were shown in Table 18. The mixture was stirred at room temperature at 300 rpm prior to coating. The mixtures all formed clear colorless solutions.

Table 18 sample Ti(OC ₂ H ₅ )4(mL) 2.16M TEOS(mL) Ethanol (mL) P123(g) HCl(mL) 1 7.59 0.00 77.2 4.62 0.57 2 6.64 2.13 77.2 4.62 0.57 3 7.59 0.00 77.2 1.00 0.57 4 6.64 2.13 77.2 1.00 0.57 5 7.59 0.00 77.2 0.00 0.57 6 6.64 2.13 77.2 0.00 0.57

The molar ratios of the reagents are shown in Table 19.

Table 19 sample Ti(mol) Si(mol) Ethanol (mol) P123(mol) HCl (mol) water (mol) 1 1 1 35.7 0.022 0.188 0.650 2 0.825 0.125 35.7 0.022 0.188 0.650 3 1 1 35.7 0.0047 0.188 0.650 4 0.825 0.125 35.7 0.0047 0.188 0.650 5 1 1 35.7 0.0 0.188 0.650 6 0.825 0.125 35.7 0.0 0.188 0.650

The above coating solution was filtered and coated onto a substrate as described in Example 1. The film was dried at room temperature for 1 day.

For films on silicon substrates, thickness and refractive index were measured at 50° and 70° as described above. The coated films on silicon and glass were calcined at 700°C for 1 hour. Contact angle, refractive index, and thickness were again measured. The approximate volume % of surfactant in the coating mixture is calculated as above. Thickness, refractive index, % porosity, and volume % surfactant in coating solution for films on silicon are shown in Table 20.

Table 20 sample t25℃() n25℃ T700℃() N700℃ %P at 700°C V%Surf 1 3004 1.40 1920 1.49 55 86 2 3338 1.51 948 1.79 31 85 3 2792 1.58 1026 1.95 25 57 4 3143 1.44 994 1.70 39 56 5 1795 1.66 752 2.13 16 0 6 1739 1.66 739 2.08 14 0

For samples on glass, the contact angle was monitored over 15 days. The samples were placed horizontally in a Petri dish on a laboratory bench. Unless otherwise stated, the contact angle data stated in Table 21 are for the upward (top) side of the sample. The photocatalytic data in Table 21 were collected after calcination as described above. The samples were UV treated with a UVB black lamp (~2.0 mW/C _m ² ) for 30 minutes. The pencil hardness data in Table 21 were also measured on all calcined samples using the method described above.

Table 21 sample CA(°) CA(°) Photocatalytic data pencil hardness XRD XRD Total days since made 1 15 14 Calcined at 500℃ cover Initial slope (intensity/minute) 2θ<5° 20°＜2θ＜60° 1 3 18 288000 <6B - A 2 5 11 56000 f - 3 10 19 185000 6H - A 4 5 8 55000 HB - 5 17 25 255000 7H - A 6 10 29 11000 >9H -

Example 6

Mix titanium alkoxide (TET-titanium tetraethanolate; TPT-titanium propoxide), absolute ethanol, concentrated hydrochloric acid or 1 wt% hydrochloric acid, acetic acid (1 wt% in water), deionized water, and P123 in 250 mL of polypropylene In the bottle, its amount is as shown in table 22. The mixture was stirred at room temperature at 300 rpm prior to coating.

Table 22 sample Ti source Titanium alkoxide (mL) Ethanol (L) P123(g) 1% acetic acid aqueous solution (mL) HCl(L) 1% HCl aqueous solution (L) water 1 TPT 5.02 53.0 1.23 0.34 0.37 2 TPT 5.13 54.1 0.35 0.38 3 TPT 2.37 47.9 1.67 5.43 2.61 4 TPT 2.44 49.3 5.58 2.69 5 TET 5.33 54.2 0.40 6 TET 5.06 51.5 3.08 0.38

The molar ratios of the reagents are shown in Table 23.

Table 23 sample Ti(mol) Ethanol (mol) P123(mol) Acetic acid (mol) HCl (mol) water (mol) 1 1 64 0.0167 0.29 2.45 2 1 64 0.29 2.45 3 1 136 0.048 0.131 25.55 4 1 136 0.134 0.131 25.55 5 1 45 0.0 0.134 0.232 0.81 6 1 45 0.03 0.232 0.81

Coating was performed as described in Example 1. The film dries within 1 minute. The film was dried at room temperature for 1 day.

Then, the film was calcined at 500°C for 1 hour. Contact angles were monitored for 25 days. The samples were placed horizontally in a Petri dish on a laboratory bench. The contact angle data are for the downward facing side (lower surface) of the film. The films were exposed to UV radiation twice, and the contact angles were measured after each exposure, as shown in Table 24. X-ray diffraction was performed on the film. The Bragg peak is notably absent, except for a very weak broad feature at ~150 Å for sample 1.

Table 24 sample CA(°) CA(°) CA(°) CA(°) CA(°) Total days since made 0.5 1 7 8 26 Calcined at 500℃ UV exposure for 21 hours cover UV exposure for 24 hours cover 1 0 0 7 0 15 2 0 0 7 20 35 3 0 0 10 0 12 4 0 0 11 17 15 5 0 0 6 0 17 6 0 0 13 0 8

Example 7

Mix titanium ethoxide, absolute ethanol, surfactant and concentrated hydrochloric acid in a 250 mL polypropylene bottle, and the amounts are shown in Table 25. The mixture was stirred at room temperature at 300 rpm prior to coating. The mixtures all formed clear colorless solutions.

Table 25 Sample (surfactant) Ti(OC ₂ H ₅ )4(mL) Ethanol (mL) Surfactant (g) HCl(mL) 1(P123) 7.59 77.2 4.62 0.57 2(P103) 7.59 77.2 4.62 0.57 3(10R5) 7.59 77.2 4.62 0.57 4(C ₁₆ TAB) 7.59 77.2 4.62 0.57

The molar ratios of the reagents are shown in Table 26.

Table 26 sample Ti(mol) Ethanol (mol) Surfactant (g) HCl (mol) water (mol) 1(P123) 1 35.7 0.022 0.188 0.650 2(P103) 1 35.7 0.025 0.188 0.650 3(10R5) 1 35.7 0.064 0.188 0.650 4(C ₁₆ TAB) 1 35.7 0.34 0.188 0.650

The above coating solution was filtered and coated onto a substrate as described in Example 1. The film was dried within 1 minute and the film was dried at room temperature for 1 day. Films prepared using solutions containing _C16TAB were off-white. The dipping rate was slowed to 0.35C _m /min, the coating was still hazy,

For films on silicon substrates, thickness and refractive index were measured at 50° and 70° as described above. Then, the film was treated at 500° C. for 1 hour. Contact angle, refractive index, and thickness were again measured. The approximate volume percent of surfactant in the coating mixture was calculated to be 86%, as described above. The thickness and refractive index used for the films on the silicon substrate are shown in Table 27.

Table 27 sample t25℃() n25℃ t500℃() n500℃ %P at 500°C V%Surf 1 3525 1.57 2074 1.37 65 86 2 3477 1.54 1718 1.45 58 86 3 3440 1.63 1251 1.60 47 86 4 3677 1.59 374 1.87 29 86

For samples on glass, the contact angle was monitored over 15 days. The samples were placed horizontally in a Petri dish on a laboratory bench. Unless otherwise stated, the contact angle data stated in Table 21 are for the upward (top) side of the sample. The data for the films on glass are shown in Table 28.

Table 28 sample CA(°) CA(°) CA(°) CA(°) CA(°) Total days since made 1 2 7 14 14 as made Calcination at 500°C for 1 hour cover cover UV exposure for 10 minutes 1 twenty one 3 5 15 9 2 twenty four 3 6 7 4 3 16 6 4 6 4 4 16 4 6 4 3

Example 8

Titanium ethoxide, absolute ethanol, P123 and concentrated hydrochloric acid, and TiO2 or SiO2 nanoparticles were mixed in a 250 mL polypropylene bottle, and the amounts were shown in Table 29. The mixture was stirred at room temperature prior to coating. The solutions were spin-coated onto silicon wafers and glass slides at 2000 rpm (30 seconds).

Table 29 sample Ti(OC ₂ H ₅ )4(mL) TiO ₂ (g) SiO ₂ (mL) Nanoparticle diameter (nm) Ethanol (mL) P123(g) HCl(mL) Inorganic particles V% 1 2.53 - - ^30a 25.7 1.54 0.19 2 2 2.53 2.13 - ^30a 25.7 1.54 0.19 2 3 2.665 - - ^30a 27.1 - 0.20 2 4 2.665 2.19 - ^30a 27.1 - 0.20 2 5 (control) - 30 - ^30a - - - 100 6 2.53 2.13 - ^8b 25.7 1.54 0.19 17 7 2.665 2.19 - ^8b 27.1 - 0.20 16 8 2.53 2.13 - ^9c 25.7 1.54 0.19 18 9 2.665 2.19 - ^9c 27.1 - 0.20 17 10 2.53 2.13 - 12 ^d 25.7 1.54 0.19 17

11 2.665 2.19 - 12 ^d 27.1 - 0.20 17 12 2.53 2.13 - ^30a 25.7 1.54 0.19 2 13 2.665 2.19 - ^30a 27.1 - 0.2 2 14 8.00 81.4 0.00 0.60 15 7.59 77.2 4.62 0.57 16 8.00 - 1.50 ^20e 81.4 0.60 26 17 7.59 - 1.50 ^20e 77.2 4.62 0.57 27 18 3.79 3.20 ^30a 38.6 2.31 0.29 2 19 4.00 3.29 ^30a 40.7 0.30 2 20 30(2.16MTEOS) 60 8.61 twenty one 30(2.16MTEOS) 60 0.00

^a Titanium dioxide-antimony (80/20 w/w) nanoparticles, 1% in water (prepared as described in PCT publication WO 03/045846, published June 5, 2003, under automatic pressure, at 150-200°C );

^b Optolake 3 (No. S299015) zirconia-coated anatase (10% solids) from Catalyst and Chemicals Ind. Co., Ltd, Saiwai-Ku, Kawasaki City, Japan;

^c Optolake 1 (No. S299013) (9.9% solids) from Catalyst and Chemicals Ind. Co., Ltd, Saiwai-Ku, Kawasaki City, Japan;

^d Optolake 2 (No. S299014) tin species rutile (10.9% solids) from Catalyst and Chemicals Ind. Co., Ltd, Saiwai-Ku, Kawasaki City, Japan;

^e Nalco 1042 colloidal silica (-30% solids), Nalco Chemical Co., Naperville, IL.

Note: In Sample 4, the particles started to settle before coating.

For sample 113, the refractive index was measured at 50° and 70° as described above. Then, the film was heated at 250° C. for 15 minutes, and the refractive index was measured again. The membrane was heated at 500° C. for 1 hour on the third day. Measure contact angle, refractive index and thickness. The samples were left covered for an additional week and the contact angle was measured. After one week, the samples were treated with UV light for 16.5 hours as described above. The thickness and refractive index data are shown in Table 30; the contact angle data are shown in Table 31.

Table 30 sample n25℃ n250℃ t500℃() n500℃() 1 1.38 1.53 1393 1.60 2 1.58 1.37 1483 1.54 3 1.83 1.82 736 1.76 4 1.86 1.82 896 1.79 5 1.85 1.62 336 1.69 6 1.90 1.52 2033 1.42 7 1.75 1.75 885 1.88 8 2.17 1.46 1818 1.41 9 1.75 1.76 780 1.90 10 1.88 1.76 1485 1.50 11 1.75 1.73 846 1.90 12 1.59 1.66 1415 1.49 13 1.63 1.78 618 1.90

Table 31 sample CA(°) CA(°) CA(°) CA(°) CA(°) Total days since made 0 1 3 10 10 as made Calcination at 250°C for 15 minutes Calcination at 500°C for 1 hour (2 days in total) Covering (7 days after calcination at 500°C) UV irradiation for 16.5 hours (7 days after calcination at 500°C) 1 twenty one 9 12 8 5 2 twenty two 10 5 6 5 3 43 28 8 10 3 4 29 20 6 10 2

5 11 13 9 8 6 6 twenty one 7 9 7 3 7 12 49 5 7 3 8 19 8 5 9 4 9 29 twenty three 17 6 4 10 18 10 3 6 6 11 27 twenty two twenty four 15 3 12 15 9 4 12 4 13 6 26 5 26 3

For samples 14-17 (films on silicon substrates), the refractive index was measured at 50° and 70° as described above. Then, the film was heated at 250° C. for 1 hour, and the thickness and refractive index were measured again. The samples were left for 4 days and the contact angle was measured. The samples were treated with UV light for 16.5 hours as described above. Thickness and refractive index data are shown in Table 32; contact angle data are shown in Table 33.

Table 32 sample t25℃ n25℃ t250℃() n250℃() 14 1710 1.76 1180 1.90 15 1809 1.62 1915 1.48 16 1813 1.85 1567 1.72 17 1629 1.65 1705 1.44 18 1840 1.51 1465 1.48 19 1463 1.92 1098 1.93 20 1997 1.40 1992 1.45 twenty one 2188 1.46 2811 1.42

Table 33 sample CA(°) CA(°) CA(°) CA(°) Total days since made 1 3 7 8 as made Calcination at 250°C for 1 hour not covered UV exposure for 16.5 hours 14 26 20 62 10 15 18 7 13 13 16 14 14 58 2 17 20 6 5 3 18 13 12 18 9 19 17 14 54 8 20 54 17 13 16 twenty one 73 47 35 39

Several samples on glass slides were tested with a Taber grinder using a ~1 _cm wide single-arm grinding wheel loaded with a fixed weight. The samples were mounted on a 3 inch by 3 inch clear plastic square substrate with a hole in the center. The samples were then placed on the grinder and spun up to 1160 revolutions. Haze (ie, light attenuation) was measured at several intervals with a nephelometer. Data are listed in Table 34. The data show that the membrane is completely removed after <100 revolutions.

Table 34 sample Haze% Haze% Haze% Haze% Haze% Haze% Haze% change 0 10 20 40 80 160 1160 1 9.7 19.6 18.2 14.3 11.2 9.7 11.4 3 4.1 4.5 4.9 5.7 6.5 7.7 5.5 6 2.6 16.0 12.4 6.4 4.3 4.2 4.6 12 4.8 14.3 10.5 12.2 8.6 8.1 8.6 13 3.3 7.3 6.8 5.7 4.1 3.8 4.9 17 2.5 5.7 4.9 4.5 4.7 4.7 5.5 18 3.2 14.2 8.8 5.1 4.1 4.1 4.7 19 65.1 38.8 38.5 37.7 39.1 39.2 38.4 20 6.2 8.6 5.2 4.1 5.6 4.5 6.4

Comparative example 3

P123 (1 g) and absolute ethanol (10 g) were added to a 20 mL glass vial and stirred for ~45 minutes to dissolve the surfactant. After cooling, _TiCl4 (1.1 mL) was added slowly, forming a clear yellow solution. The molar ratio of the reagents is: 1Ti: 18.7 ethanol: 0.019. The solutions were heated to 30°C for 10 minutes and then spread onto silicon wafers and glass slides. The solution was spin-coated at 2000 rpm for 30 seconds. After heating at 250°C for 15 minutes and at 500°C for 1 hour, the contact angles on the prepared samples were measured. The contact angles are 36°, 10° and 34°, respectively.

Claims (22)

1. A surfactant-mediated membrane comprising: Surfactant-mediated nanoporous metal oxide films have no Bragg XRD peaks at less than 5°2θ using CuK _α radiation. 2. A hydrophilic article comprising: The surfactant-mediated film of claim 1 on a substrate. 3. The film as claimed in claim 1 or the hydrophilic article as claimed in claim 2, wherein said metal oxide comprises silicon, titanium, zirconium, hafnium, vanadium, molybdenum, tungsten, magnesium , iron, cobalt, nickel, copper, zinc, aluminum, gallium, indium, germanium, tin, arsenic and antimony metal oxides and combinations thereof. 4. The membrane of claim 1 or the hydrophilic article of claim 2, wherein the membrane has a contact angle with water of less than 10°. 5. The membrane of claim 1 or the hydrophilic article of claim 2, further comprising nanoparticles. 6. The film or article of claim 5, wherein the nanoparticles comprise metal oxides selected from the group consisting of silica, titania, and combinations thereof. 7. The membrane of claim 1 or the hydrophilic article of claim 2, wherein the membrane has a thickness of 10 nm to 1 micron. 8. The membrane of claim 1 or the hydrophilic article of claim 2, wherein the membrane has a porosity of 30-90%. 9. The film of claim 1 or the hydrophilic article of claim 2, wherein the film has a refractive index of 1.2-2.15. 10. The film or article of claim 5, wherein the film has a refractive index of 1.35-2.1. 11. The article of claim 2, wherein the substrate is selected from the group consisting of metal, colored metal, glass, ceramic, plastic, and wood. 12. A method for making the surface of a workpiece super-hydrophilic, said method comprising the steps of: providing a surfactant-mediated metal oxide film precursor comprising an alkoxide of titanium dioxide, cationic and nonionic surfactants, and an acid catalyst; coating the precursor onto the surface of the article; drying the precursor; and The surfactant is removed. 13. The method of claim 12, wherein the surfactant is removed by heating the coated article at about 200-850°C. 14. The method of claim 12, wherein the precursor further comprises an alkoxysilane. 15. The method of claim 12, wherein the precursor further comprises nanoparticles. 16. The method according to claim 12, wherein the surfactant is selected from the group having the general formula C _n H _2n+1 N(CH ₃ ) ₃ X, wherein X is OH, Cl, Br, HSO ₄ or a combination of OH and Cl, n is an integer of 8-22; C _n H _2n+1 N(C ₂ H ₅ ) ₃ X, where X is OH, Cl, Br, HSO ₄ or OH and Cl A combination of alkyl ammonium salts where n is an integer of 12-18; a surfactant having the general formula (C ₁₆ H ₃₃ N(CH ₃ ) ₂ ) 2C _m H _2m 2X, wherein X is OH, Cl, Br, HSO ₄ , m is an integer of 2-12; hexadecylethylpyridinium salt with general formula C ₁₆ H ₃₃ N(C ₂ H ₅ )(C ₅ H ₁₀ )X, where X is OH, Cl, Br, _HSO4 or a combination of OH and Cl; poly(ethylene oxide), (octaethylene glycol) monolauryl ether, (octaethylene glycol) monohexadecane poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, poly(propylene oxide)-poly(ethylene oxide)-poly(epoxide Propane) triblock copolymers and combinations thereof. 17. The method of claim 12, wherein the surfactant is selected from the group consisting of poly(ethylene oxide), (octaethylene glycol) monododecyl ether, (octaethylene glycol) Glycol) monocetyl ether, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, poly(propylene oxide)-poly(ethylene oxide) Alkane)-poly(propylene oxide) triblock copolymers and combinations thereof 18. The article of claim 2, further comprising a barrier film disposed between the substrate and the surfactant-mediated film of claim 1. 19. The article of claim 18, wherein the barrier film comprises silicon dioxide or silicone. 20. The article of claim 2, wherein the surfactant-mediated film is regenerated by exposure to UV light. 21. The article of claim 2, wherein the surfactant-mediated film provides anti-reflective properties. 22. The article of claim 2, wherein the surfactant-mediated film is a layer in an antireflective stack.

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